Warming from loss of Arctic albedo

[Abraham3]

you have a warped sense of the scientific method.

I disagree

hypotheses are put forward to make an effort to explain the available data.

Yes.

it [sic] is then the job of the scientist to defend his idea against all comers, and test his idea against new evidence. if [sic] the idea holds up long enough and the majority of new evidence supports it, it becomes a theory. but [sic] it is never exempt from being questioned, never exempt from having to defend itself. [Please capitalize the first word in each sentence - aids readability]

You have the order a little out of whack. Attacking someone's emergent hypothesis would be unfair and counterproductive. I think the originator has the initial responsibility to test his hypothesis and it is not until he wishes to put it before his peers via publication that he is throwing himself open to "all comers" and inviting his peers to attempt to reproduce his work. Now I am sure that researchers discuss and criticize each other's ideas at all stages of the process, but, in general, I believe researchers give each other the opportunity to get their work together to their own[/u satisfaction before pulling out their pop-guns and taking potshots at it.

Of course none of that is true among AGW deniers. To them, all is fair game and any tactic is acceptable as long as it hurts the enemy and slows acceptance of AGW among the voting and taxpaying public.

physics has a mechanism whereby increasing CO2 should warm the surface and atmosphere, if all other variables remain the same. temperature increases in the 80's and 90's gave credence to the predictions of global warming. ever more exaggerated predictions came out with the physics calculations for doubled CO2 being multiplied by positive feedbacks. the 00's and 10's have provided evidence that CO2 is not the control knob for climate, and may only be a small factor.

The evidence supporting the contention that transient climate sensitivity to CO2 is on the order of 2.5C - 5C (and recent work is pushing the centroid of that prediction upward) comes from the temperature record of the last 150 years, not two decades. With evidentiary value decreasing with decreasing age, support for those values also comes from paleo data going back millenia. What YOU should try to concentrate on - to get into your head - is that it is not smaller than that and it is not - as many of your brethren have attempted to contend - ZERO.

just because CO2 induced global warming became the paradigm by the TAR IPCC report, that doesnt mean that it no longer had to defend itself! since then many legitimate questions have been asked only to be ignored by claiming 'consensus!' or 'denier!'.

The knowledge we have - the current understanding and the current range of values climate scientists hold for sensitivity is the result of precisely the sort of process you describe. That few if any researchers are spending their time attempting to show that sensitivity is zero or that the Greenhouse Effect is not real or that humans are not the primary cause of our warming is simply the result of all that having become accepted science. And it is NOT accepted science because Phil Jones or Michael Mann said it was. It's accepted science because that is what a broad application of the scientific method has shown it to be. It has NOT been falsified. It has NOT been superseded or replaced. It IS the best explanation for all the observations. It has, in your jargon, stood up to all comers.

this thread is about a paper that documents the albedo decrease in the Arctic over the last few decades but mostly since CERES came on line. I asked a perfectly legitimate question. does Arctic albedo decrease also show up as part of global albedo decrease?

From Wikipedia's article on albedo:

"The average overall albedo of Earth, its planetary albedo, is 30 to 35% because of cloud cover, but widely varies locally across the surface because of different geological and environmental features.[1]"

1) Environmental Encyclopedia, 3rd ed., Thompson Gale, 2003, ISBN 0-7876-5486-8

So, the answer is that the Earth's albedo is not known with sufficient precision to say. Perhaps it will be soon. It will require as in depth a study as was conducted here for the Arctic. That shortcoming does nothing to refute the conclusions of this study. The albedo of the Arctic has reduced significantly and given the concommittant loss of ice and snow worldwide, it is completely reasonable to assume that global albedo, even without the effect of Arctic ice loss, may also be headed downward. Changes in cloud cover, of course, are a major factor in our uncertainty and the wide variability of the value you demand we pin down.

I also asked whether decreased albedo shortwave was compensated by increased longwave. both are important questions that go to the heart of the conclusion 'loss of arctic ice is a positive feedback'. if global albedo is not down then the arctic has been compensated for elsewhere. if longwave has gone up more than shortwave has gone down then loss of ice is a negative feedback. I then suggested that the same type of data study be done for Antarctica as a control to see if scientific understanding of the radiative balances for ice loss/gain were supported.

All lovely questions and if one of us had a subscription to PNAS we might know what this paper had to say on any of them. But I can't help but think that you only ask them because you hope to throw doubt on the paper without actually examining anything IT said.

I finished by thinking outside the box and wondering if the scientific world might not be backwards in thinking which case was a positive/negative feedback.

And such "thinking outside the boox would be unwarranted speculation. Fee free to make it but don't be surprised if very few pay you any attention.

I am not a climate scientist but I have seen enough lame ad hoc excuses produced in the last ten years to know that there is a huge pressure in climate science to shore up CAGW, even at the cost of scientific integrity.

This study had nothing to do with anthropogenic global warming per se - simply a consequence of the ice loss experienced in the Arctic over the last 30 years. So it was not shoring up a damn thing. The study was an analysis of data in the public record extracting a parameter heretofore unexamined quantitatively.

Those ad hoc excuses you keep hearing are not coming from climate scientists. They are coming from the denier camp throwing up their "special' interpretations when they find some evidence susceptible to such twisting and often without even that. AR5 is a large and thorough summation of mainstream science's current understanding. If the process has been driven along with the assistance of ad hoc excuses, the work should be rife with them. Find us one.